UNITED NATIONS (AP) — Israeli Prime Minister Benjamin Netanyahu played the spoiler Tuesday to Iran’s attempts to ease relations with the West, calling the Iranian leader “a wolf in sheep’s clothing” and declaring that Israel will do whatever it takes to prevent Tehran from developing nuclear weapons, even if it has to stand alone.

Speaking to world leaders at the U.N. General Assembly, Netanyahu gave a point-by-point rebuttal of President Hassan Rouhani’s speech last week signaling a willingness to discuss Iran’s disputed nuclear program.

Accusing Rouhani of a “charm offensive” aimed at getting the West to lift crippling sanctions, Netanyahu portrayed him as “a loyal servant of the regime” who has done nothing to stop his country’s nuclear program since he took office in June.

Rouhani, he added, must have known about terrorist attacks carried out by Iranian agents in Argentina, Saudi Arabia and Berlin in the 1990s because he was national security adviser at the time.

Israel’s hope for the future is challenged “by a nuclear-armed Iran that seeks our destruction,” the Israeli leader said.

A year ago at the General Assembly, Netanyahu held up a drawing of a spherical bomb with a sputtering fuse, then pulled out a red marker and drew a line across what he said was the threshold Iran was fast approaching and which Israel would not tolerate — 90 percent of the uranium enrichment needed to make an atomic bomb.

“Iran has been very careful not to cross that line,” Netanyahu said Tuesday. “But Iran is positioning itself to race across that line in the future at a time of its choosing.”

“I wish I could believe Rouhani, but I don’t because facts are stubborn things, and the facts are that Iran’s savage record flatly contradicts Rouhani’s soothing rhetoric.”

He pointed to Iran’s continuing enrichment of uranium to a 20-percent level, its addition of thousands of new centrifuges and its development of intercontinental ballistic missiles “whose sole purpose is to deliver nuclear warheads” that the U.S. says will be capable of reaching New York in three or four years.

“Israel will never acquiesce to nuclear arms in the hands of a rogue regime that repeatedly promises to wipe us off the map,” Netanyahu declared. “I want there to be no confusion on this point: Israel will not allow Iran to get nuclear weapons. If Israel is forced to stand alone, Israel will stand alone.”

After his address, Netanyahu, like Rouhani, received warm applause but Iran’s seat in the assembly chamber was empty, as it continued its longstanding boycott of Israeli speeches.

Iran exercised its right of reply later, with Khodadad Seifi, a deputy ambassador to Iran’s U.N. mission, accusing Netanyahu of “saber rattling” and warning that he should “avoid miscalculation.”

“Iran’s centuries-old policy of non-aggression must not be interpreted as its inability to defend itself,” Seifi said. “The Israeli prime minister had better not even think about attacking Iran, let alone planning for that.”

He reiterated Iran’s readiness to engage in “meaningful, time-bound and result-oriented negotiations” and “to ensure that its nuclear program will continue to remain exclusively peaceful.”

“Over the past 22 years … Israel has been saying Iran will have nuclear arms in six months,” said Zarif, speaking in New York in an interview broadcast on Iranian state TV. “The continuation of this game, in fact, is based on lying, deception, incitement and harassment.”

At the White House, press secretary Jay Carney said Netanyahu’s skepticism about Iran and its intentions is “entirely justifiable” because until recently Iran’s leadership “was pledging to annihilate Israel.”

The U.S. shares Israel’s goal of keeping Iran from obtaining a nuclear weapon, Carney said. He stressed that President Barack Obama will be “very firm” on demanding verifiable, transparent action to ensure that Iran has given up its nuclear weapons ambitions.

Netanyahu warned that a nuclear-armed Iran would have a choke-hold on the world’s main energy supplies.

“It would trigger nuclear proliferation throughout the Middle East, turning the most unstable part of the planet into a nuclear tinderbox. And for the first time in history, it would make the specter of nuclear terrorism a clear and present danger,” the Israeli leader said.

Netanyahu said the greater the pressure, the greater the chance for diplomacy to succeed. The only diplomatic solution, he said, is one that requires Iran to completely dismantle its nuclear weapons program and prevents it from starting one in the future.

This would require a halt to all uranium enrichment, removing uranium stockpiles from Iran, dismantling the infrastructure for “nuclear breakout capability” — reaching the point where the country can make a quick dash to a nuclear weapon.

He also said it would require stopping all work at a heavy water reactor aimed at producing plutonium, which like uranium can be used to produce nuclear weapons, he said.

At the U.N. last week, Rouhani presented a more moderate face of the hard-line clerical regime in Tehran.

He agreed to the first nuclear talks with six world powers since April at a meeting Thursday on the sidelines of the General Assembly, where Zarif and U.S. Secretary of State John Kerry met privately. On Friday, Rouhani and Obama spoke on the phone for 15 minutes, the highest-level contact between the two countries in 34 years.

But Netanyahu said Rouhani’s goal was the same as his hard-line predecessor, Mahmoud Ahmadinejad.

“Ahmadinejad was a wolf in wolf’s clothing. Rouhani is a wolf in sheep’s clothing, a wolf who thinks he can pull the wool over the eyes of the international community,” Netanyahu said.

All Iranian presidents serve the same “unforgiving regime” where the supreme leader, Ayatollah Ali Khamenei, is a dictator and the real power, Netanyahu said.

Netanyahu asserted that Rouhani must have known about the murder of 85 people in a terror attack on the Jewish Community Center in Buenos Aires in 1992, as well as the killing of 19 American soldiers in Saudi Arabia in 1996 and the slaying of Iranian opposition leaders in Berlin in 1992 because he was head of Iran’s Supreme National Security Council from 1989-2003.

The U.S. has also accused Iran of sponsoring acts of terrorism around the world throughout the 1990s, blaming Iran and its proxy Hezbollah for a 1992 attack on the Israeli Embassy in Buenos Aires that killed 29 people, as well as the community center attack two years later. Some analysts linked Iran’s Quds Force to helping direct the 1996 bombings of the Khobar Towers in Saudi Arabia that killed 19 American military personnel.

Netanyahu said Rouhani condemned the “violent scourge” of terrorism. “Yet in the last three years alone, Iran has ordered, planned or perpetrated terrorist attacks in 25 countries on five continents,” he charged, without providing any evidence.

He also accused Iran of lamenting the human tragedy in Syria, while at the same time directly participating in President Bashar Assad’s murder and massacre of tens of thousands of innocent men, women and children. He said Iran is propping up a Syrian regime that just used chemical weapons against its own people.

He said Rouhani denounced attempts to change the regional balance in the Middle East through proxies. “Yet Iran is actively destabilizing Lebanon, Yemen, Bahrain and many other Middle Eastern countries,” Netanyahu said.

He cited an attempt by Iranian agents to assassinate Saudi Arabia’s ambassador to the United States in Washington two years ago, and the arrest of an Iranian agent three weeks ago trying to collect information “for possible attacks against the American Embassy in Tel Aviv.”

Israel’s Shin Bet security agency says Iran recruited the Belgian-Iranian national Ali Mansouri last year and sent him to Israel to spy. He was arrested on Sept. 11 at Israel’s international airport.

A lawyer for Mansouri said the allegations are baseless.

Israel announced the arrest on Sunday as Netanyahu left for the U.S. Israeli media have speculated that the timing of the announcement was politically motivated. ___

Associated Press writers Peter James Spielmann and Marjorie Olster contributed to this report.